OK lets look at this post. I obviously left some things out I shouldn't have, and will point out some other things.
1. NEVER EVER use a stock pan with a filled block. EVER. I always use at least 8 quarts. You can't cool an engine with 4 quarts in the pan. The oil spends too much time in the engine. Mistake number 1.
2. A 3 core radiator means little. Fin count, tube diameter, multiple pass etc. all make a difference. You damn sure should have had an 8 blade water pump, preferably the Milodon part number, which has the back of the impeller closed off. You'd be surprised what closing off the back of the impeller does for water flow, and FLOW is everything.
3. Since I do this for a living I don't always give all the details I probably should. If you fill the block and don't want to run 8 quarts of oil you either MUST run 20w50 oil (or even 20w60 or better yet, Torco makes a 10w60 that would be perfect) or you MUST close up bearing clearances. A scuffed bearing or a spun bearing only happens because of lack of oil.
4. You MUST also increase piston to wall clearance. The cylinders flex less and grow less so clearance must be opened up.
If you follow simple rules you can fill a block and GAIN HP. But you can't skimp. If you do, it will cost you in spades.